John Berry had long been curious why his World War II veteran father always had a tear in his eye when he spoke about Australia.
His dad was among American defence personnel at Guadalcanal in the Solomon Islands and his three weeks leave in Australia and the warmth of its people had reminded him there was some good left in the world.
After three years as US ambassador to Australia his son can now relate to his father's emotional response to the land down under.
"It was a tear of joy," he told the National Press Club in Canberra on Wednesday in his final address before wrapping-up his posting.
"I suspect I will always have one in mine when I remember my time in this blessed lucky country."
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Mr Berry vowed to return home to tell Americans how great Australia is, but he also has a reciprocal message - aimed at those fixating on China's rise and forecasting America's downfall.
"America is and always will be a Pacific and global power," he said.
"We will remain a rising power for generations to come."
Mr Berry declared the US foreign policy "rebalance" to the Asia-Pacific region of recent years should "now rightfully be called the new normal".
The US-Australia alliance and co-operation had made both countries safer.
Intelligence sharing and co-operation at Pine Gap in central Australia had helped foil far more terrorist attacks than had occurred.
"We will not rest until that number is 100 per cent," he said.
Reflecting on the upcoming US presidential election, Mr Berry was full of praise for Australia's unique electoral system especially compulsory voting, a time limit on campaigns and parliamentary boundaries set by an independent commission.
"If adopted in America (those reforms) would make my country stronger," he said.
Co-operation between Australia and US astronauts and scientists was essential to the greatest human endeavour of this century, Mr Berry said.
"When we go to Mars, and we will - all communications will be managed right here at Tidbinbilla (in the ACT)," he said.
Mr Berry will return to the US to take up a role as president of the American Australian Association.
